There were some sweaty collars at Pinsent Masons this week after one of the firm's clients was accused of propping up the Ukranian president.

One of President Yanukovych's greatest supporters is Dimitry Firtash, an oligarch who has bankrolled him for many years. And done very well out of it too: he has acquired a number of state assets since Yanukovych came to power, and was appointed head of the National Tripartite Social and Economic Council in 2012.

Firtash's business contacts are with Russia, and he has supported Yanukovych in moving away from the EU - a decision which threatens to drive the country into civil war. And whilst not quite in Assad territory, Yanukovych presides over a pretty brutal regime. Two protestors were shot dead by police on Wednesday, and the body of another was discovered in a forest outside Kiev showing signs of torture.

Kiev yesterday

All of which makes for uncomfortable reading for Pinsent Masons, given that it acts for Firtash. While there's no suggestion that the firm has broken any rules in acting for him, City firms which take money from rich but dubious clients tend to suffer PR disasters as a result: Penningtons never lived down representing the President of Equatorial Guinea.

A spokesman for the firm said "it is not our policy to discuss client confidential matters. However, as an international firm active in the energy and natural resources sector, it is to be expected that we carry out substantial work for clients in Eastern Europe, many of whom will necessarily have relations with political administrations. As you would expect we follow strict procedures before accepting instructions from politically exposed persons and will decline to act if we have concerns."